Auxiliary systems of electric locomotives and EMUs mainly have two methods of taking power, from auxiliary windings of main transformer and from DC-link of traction converter. A novel scheme is proposed which makes power of regenerative braking supply to auxiliary winding in order to guarantee auxiliary system which gets power from auxiliary winding achieve uninterrupted power supply and can avoid overvoltage and inrush current when passing neutral section. Furthermore, this scheme achieves uninterrupted auxiliary power supply simply by modifying the locomotive's control strategy. Simulation and experimental results verified the feasibility of the proposed scheme.

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What is the effect of the structural length scale on the ordering of 3 He films? NMR experiments on the magnetism of second layer 3 He on Grafoil in the low field limit found ferromagnetic ordering for coverages over 20 atoms/nm 2. Finite temperature phase transitions are prohibited in 2D when only Heisenberg interactions are present. However ordering of a two-dimensional magnetic film can be a result of a phase transition caused by weak anisotropy and/or dipolar interactions, or could be a less interesting manifestation of finite size effects. By replacing Grafoil with ZYX grade highly oriented graphite we can study the magnetism of two-dimensional films with a substantially increased structural coherence length and test the importance of finite size effects. Our new experiments find a region of coverages where the second layer 3 He films become ferromagnetic at temperatures above 1 mK, with no evidence for an increased suppression of the ordering due to increasing the coherence length. We show the results for the magnetism at a wide range of coverages as well as the effect of varying the magnetic field in the ferromagnetic cases. Our results support the interpretation in terms of a phase transition occurring at finite temperature.